Is it true a health condition that results in a disability for one individual may not result in a disability for another individual with the same condition?

It is true that the same health condition in one individual may result in a disability and not in another. First, one must have a working definition of disability to compare the individuals. The U. S. Social Security Administration (SSA) identifies the three components of the strict definition of disability as being:

"Disability" under Social Security is based on your inability to work. We consider you disabled under Social Security rules if:

You cannot do work that you did before;

We decide that you cannot adjust to other work because of your medical condition(s); and

Your disability has lasted or is expected to last for at least one year or to result in death.

This is a strict definition of disability. ...(US Social Security Administration)

In addition, the individual must have been seen for their condition, such that there is information for substantiation. Finally, if one has been or is being treated such that it is determined they have a disability, then that determination is required for the SSA's decision on disability.

There are so many factors within people's backgrounds--employment, education, socio-economic status, support from others--that it would be incorrect to say the same health condition existing in two people always results in the same disability in each.

If someone has her finger chopped off, yet her education and employment allow her to function in earning a living so that this not a disabling impairment, then she does not meet the SSA definition of having a disability. Another person with the same injury, who has lesser education and lesser training, producing lesser options, may be determined to be disabled because the Social Security Administration definition is met.